The use of porous particles having high surface areas, principally because of inherent high porosity, has increased markedly over the past several years. Such applications have included catalyst supports, filter media, carriers in chromatographic columns, and in immobilized enzyme composites. Considerable research has been conducted to develop porous bodies particularly useful in each specific application and wherein the range of pore diameters present therein is strictly circumscribed. Thus, porous glass has been used for such applications and U.S. Pat. No. 3,892,580 describes the manufacture of porous bodies of Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, and SiO.sub.2 wherein the size of the pores is carefully controlled. The latter bodies generally demonstrated better resistance to acids and bases than did glass.
Nevertheless, the chemical durability of porous material in a hostile environment remains a problem. The high surface area of the material offers extreme exposure opportunity for attack. This concern regarding chemical durability is especially critical in the alkaline solutions encountered where the porous material is utilized as a support for immobilized enzymes.